US3280544A

US3280544A - Method and apparatus for manufacturing roll-reduced stranded cable

Info

Publication number: US3280544A
Application number: US324028A
Authority: US
Inventors: William J Gilmore
Original assignee: American Chain and Cable Co Inc
Current assignee: FKI Industries Inc
Priority date: 1963-11-15
Filing date: 1963-11-15
Publication date: 1966-10-25
Anticipated expiration: 1983-10-25
Also published as: GB1012880A; ES305870A1; DE1510051A1; ES305865A1; BE655615A

Description

Oct. 25, 1966 J. GILMORE 3,280,544

W. METHOD AND APPARATUS FOR MANUFACTURING ROLL-REDUCED STRANDED CABLE Filed NOV. 15, 1963 INVENTOR William J. Gilmore ATTORNEYS United States Patent 3,280,544 METHOD AND APPARATUS FOR MANUFACTUR- ING ROLL-REDUCED STRANDED CABLE William J. Gilmore, Manitou Beach, Mich., assignor to American Chain & Cable Company, Inc., New York,

N.Y., a corporation of New York Filed Nov. 15, 1963, Ser. No. 324,028 3 Claims. '(Cl. 576) This invention relates to the manufacture of compacted stranded cable and, more particularly, to an improved apparatus and method for simultaneously roll-reducing stranded wires radially while pulling them from a strander head through a closing die.

Stranded cable, which may comprise one or more layers of helically disposed wires about a core wire, is often compacted radially so that the voids between the wires are substantially closed and the exposed crown portions on the exterior wires are flattened to a con siderable extent. One purpose in compacting stranded cable is to achieve the highest ratio of tensile strength to cross sectional size and another is to smooth out the otherwise ridged surface of the strand presented by its exterior wire-s. Compacted cable finds particular application as aircraft tow target line, electrical transmission core wire strands, and strands for large sizes of wire rope.

The conventional approach to the problem of compacting stranded cable has been to associate swaging dies, reducing rolls of the idling type, or draw dies with otherwise conventional rotary stranding equipment. The swage-r, idling rolls, or draw die, is located between the positively driven haul-off capstan and the closing die in which the individual wires are brought together from their spools on the strander head. After the haul-off capstan pulls the wires through the closing die to form the strand, the strand is continuously compacted and thereafter is directed to the take-up reel. It is the primary purpose of the present invention to improve on such apparatus by eliminating certain parts thereof, reducing the operating and maintenance costs, and achieving a superior compacted stranded product.

Broadly stated, the invention is directed to stranding apparatus wherein wires on a rotatable head are brought together in a closing die on the axis of rotation of the head and wrapped helically to form a strand. The improvement comprises at least one pair of opposed strand reducing rolls on the outlet side of the closing die for compacting the strand radially, and drive means for positively rotating the reducing rolls to provide the sole tractive force for pulling the wires from the head through the closing die. The invention is also directed to the method of making stranded cable wherein wires are directed through and wrapped together helically in a closing zone to form a strand. In such a method, the improvement comprises applying radial compacting forces to at least one portion of the strand at a station on the outlet side of the closing zone, and simultaneously applying longitudinal tractive forces to the strand portion at the station to pull the wires through the closing zone.

The aforementioned objects of the invention are achieved by eliminating the separate haul-off capstan which heretofore was relied upon even when radial compacting means were incorporated into the stranding apparatus. In accordance with the invention, positively driven reducing rol-ls serve to squeeze the wires of the strands together and at the same time to pull the wires through the closing zone. The initial expense and maintenance costs of a separate driven capstan are thus avoided. Also, all the wires of the strand are subjected to substantially the same elongating and compacting forces as they pass through the driven reducing rolls of the invention and there is no looseness of any wires of the resulting product, as there often is when a conventional capstan pulls the strand through a separate swager, idling rolls or draw die.

A preferred embodiment of the invention is described hereinbelow with reference to the accompanying drawing showing an elevation of the apparatus in schematic form.

, A rotary strander head indicated generally by the numeral 10 is driven by gears 11 through a shaft 12 from a motor 13. The strander head 10 may be of the conventional planetary type wherein a plurality of spools 15 are mounted in a manner well known in the art. These spools carry respective wires 16 which are drawn therefrom in the usual manner as the strander head 10 rotates and are brought together in a converging fashion at an annular closing die 17 disposed on the axis of rotation of the head 10. A spool 18 directs a core wire 19 through the center of the strander head 10 so that the wires 16 are helically wrapped together in the closing die 17 about the core wire 19. A plurality of layers of the wire 16 may be wrapped one over the other in the closing die 17 in a conventional manner, and a strand 20 is thus formed which proceeds from the outlet side of the closing die.

As mentioned previously, the conventional practice is to pull the strand 20 from the closing die 17 by means of a haul-off capstan and to subject the strand to separate radial compacting means at some point before it reaches its take-up reel. The present invention improves upon such procedures by locating a positively driven strandreducing roll unit 21 between the closing die 17 and a take-up roll 22. The unit 21 not only compacts the strand 20 but also provides the sole tractive force for pulling the wires 16 and 19 from the head 10 and through the closing die 17.

The unit 21 advantageously consists of an even number (eight in this embodiment) of pairs of opposed strandreducing rolls 25 adjacent the outlet end of the closing die 17. Each roll is formed with a circumferential groove conforming to the desired half cross section of the compacted strand 20. Every other pair of rolls is disposed in a plane perpendicular to that of the adjacent pairs thereof to subject the strand 20 to circumferentially uniform' compacting forces.

Transmission means for rotating each pair of rolls 25 is driven by the motor 13, which also is the driving means for the strander head 1 Thus, as shown schematically in the drawing, gears 26 may transmit rotary motion from the shaft 12 to the rolls in the unit 21. The transmission means inoludes one positive infinitely variable speed changing device 27 between the gears 26 and the unit 21. By adjusting the speed changing device 27, the speed of all the pairs of rolls 25 is varied with respect to the speed of the strander head 10, so that variations in the lay of the wires .16 in .the strand 20 can be achieved. The transmission means also includes a slip clutch 28 on each roll of each pair 25 thereof which governs the tractive force imparted to the strand 20. The take-up reel 22 about which the strand 20 is wrapped is of the conventional type and may be driven by any suitable means.

It should be emphasized that the value of this new strand compacting technique is not merely that it eliminates the haul-olf capstan heretofore considered indispensable, though that is a significant benefit. A feature which is perhaps even more significant is that each wire is squeezed and pulled simultaneously to a uniform extent and consequently there is no evidence in the finished strand of any looseness in the wires. In the prior art practices on the other hand, the wires of the strand are compacted either before or after they are subjected to the pull of the capstan and the incidence of looseness is appreciable. Hence, there is little or no constructional Patented Oct. 25, 1966 st-retc when the strand '20 is put to use under a tensile load because it includes no relatively tight wires which would elongate under an initially disproportionate share of the load.

I claim:

'1. In stranding apparatus wherein wires are withdrawn from respective spools revolvable about the axis of and mounted on a head which is rotatable by driving means, said wires being brought together about a core wire in a closing die on said axis and wrapped helically to form a strand of a plurality of layers, the improvement which comprises an even number of pairs of opposed grooved strand reducing rolls adjacent the outlet end of said closing die for compacting the strand radially, every other one of said pairs of rolls being disposed in a plane perpendicular to that of the adjacent pairs thereof, and transmission means driven by said driving means for positively rotating each pair of reducing rolls to supply the sole tractive force for pulling said wires from said head through said closing die, said transmission means including one positive infinitely variable speed changing means for all of said pairs of rolls and slip clutch means for each respective pair of rolls.

2. In a method of making stranded cable wherein wires are directed through and wrapped together helically in a closing zone to form a strand, the improvement which comprises applying radial compacting forces to opposite sides of at least two portions of said strand at a station on the outlet side of said closing zone, the angular direction in which the radial compacting forces are generally applied being different at the various strand portions, and simultaneously applying longitudinal tractive forces to all of the wires of the strand in each of said portions thereof at said station to pull said wires through said closing zone.

3. In a method of making stranded cable wherein wires are directed through and wrapped together helically about a core wirein a closing zone to form a strand, the improvement which comprises applying distributed radial compacting forces equally to opposite sides of a plurality of portions of said strand .at a station on the outlet side of said closing zone, the angular direction in which the radial compacting forces are generally applied being displaced at right angles from one of said strand portions to the next, and simultaneously applying longitudinal tractive forces substantially uniformly to all of the wires of the strand in each of said portions thereof at said station to pull said wires through said closing zone.

References Cited by the Examiner UNITED STATES PATENTS 1,742,172 12/1929 Atwood 57138 X 1,947,775 2/1934 Hill 571'38 X 2,079,873 5/1937 Reed 57-9 2,503,987 4/1950 Anderson 57138 FRA'NK J. COHEN, Primary Examiner.

MERVI'N STEIN, Examiner.

D. E. WATKINS, Assistant Examiner.

Claims

1. IN STRANDING APPARATUS WIRES ARE WITHDRAWN FROM RESPECTIVE SPOOL REVOLVABLE ABOUT THE AXIS OF AND MOUNTED ON A HEAD WHICH IS ROTATABLE BY DRIVING MEANS, SAID WIRES BEING BROUGHT TOGETHER ABOUT A CORE WIRE IN A CLOSING DIE ON SAID AXIS AND WRAPPED HELICALLY TO FROM A STRAND OF A PLURALITY OF LAYERS, THE IMPROVEMENT WHICH COMPRISES AN EVEN NUMBER OF PAIRS OF OPPOSED GROOVED STRAND-REDUCING ROLLS ADJACENT THE OUTLET END OF SAID CLOSING DIE FOR COMPACTING THE STRAND RADIALLY, EVERY OTHER ONE OF SAID PAIRS OF ROLLS BEING DISPOSED IN A PLANE PERPENDICULAR TO THAT OF THE ADJACENT PAIRS THEROF, AND TRANSMISSION MEANS DRIVEN BY SAID DRIVING MEANS FOR POSITIVELY ROTATING EACH PAIR OF REDUCING ROLLS TO SUPPLY THE SOLE TRACTIVE FORCE FOR PULLING SAID WIRES FROM SAID HEAD THROUGH SAID CLOSING DIE, SAID TRANSMISSION MEANS INCLUDING ONE POSITIVE INFINITELY VARIABLE SPEED CHANGING MEANS FOR ALL OF SAID PAIRS OF ROLL AND SLIP CLUTCH MEANS FOR EACH RESPECTIVE PAIR OF ROLL.